Although there are some studies concerning tuberculosis among the homeless persons in Japan, almost no detailed analysis is available about non-tuberculous lung infections in this population .
We retrospectively studied the clinical features and microbial etiology of pneumonia among the homeless. This series included twenty so-called homeless persons, 19 male and one female, who were admitted to our hospital with a clinical diagnosis of pneumonia from April 1993 to July 1996. The average age was 56 years-old. All patients were transferred by ambulance. Most of them were admitted night in the winters, and had respiratory failure together with othoer serious complications such as gastrointestinal disease, liver failure and cerebrovascular disease. Chest X ray revealed so-called lobar pneumonia in 8 of 20 cases (40%). Microbial etiologic agents were found in 14 patients (70%). Pneumococcus amounted to 80% of all the speculated pathogens. Despite intensive care after admission, 6 of 20 patients (30%) died subsequently. Although fatal pneumococcal pneumonia were reported to have decreased in the general population in Japan, morbidity and mortality of pneumococcal pneumonia was very high in this series.